| 摘要: |
| 铅(Pb)在海水中易产生沉淀,这将影响毒性实验中效应值的计算。本研究通过海水中不同重金属对中国广泛分布的底栖无脊椎动物双齿围沙蚕(Perinereis aibuhitensis)以及毒理学研究常用的海水模式生物卤虫(Artemia salina)的急性毒性实验,对比分析了海水中Pb的生物毒性特点以及暴露溶液中Pb的析出对毒性实验结果的影响。用人工海水与天然海水配制Pb溶液时,理论浓度为18.7~1 200 mg/L的Pb溶液中均出现大量白色沉淀。通过扫描电子显微镜能谱(SEM-EDS)对析出物进行检测,根据元素组成推测析出物主要为氯化铅与碳酸铅。对溶液浓度进行检测发现,Pb的实测浓度仅为理论浓度的1/15~1/2,根据实测浓度计算的Pb对双齿围沙蚕和卤虫的96 h/48 h半数致死浓度(LC50)值低于根据理论浓度计算值的1/10。对比Pb、Cu、Cd对双齿围沙蚕与卤虫的LC50值发现,Pb对水生生物的毒性低于Cu和Cd,且对不同生物的毒性效应存在差异。对比研究报道中Pb对海洋生物的急性毒性效应发现,Pb对幼体生物的毒性效应较显著,而在海水有效溶解浓度内对成体海洋生物的毒性效应较低甚至无急性毒性效应。结合Pb在海水中的析出特性及其毒性效应特点,关于海水中Pb的毒性研究应该更多地针对生物的幼体阶段,开展低暴露剂量的慢性毒性实验。 |
| 关键词: Pb 重金属 海水 析出 毒性效应 |
| DOI：10.11759/hykx20210104001 |
| 分类号:X1715 |
| 基金项目:重点研发计划(2018YFC1407603);国家自然科学基金面上项目(41373089);天津市自然科学基金项目(18JCYBJC91200) |
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| Precipitation of Pb in seawater and its impact on acute toxicity test |
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TONG Yi-fan1, HAN Xue-meng1, CAI Wen-qian2, TIAN Sheng-yan1
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1.College of Marine and Environmental Sciences, Tianjin University of Science and Technology, Tianjin 300457, China;2.State Environmental Protection Key Laboratory of Estuary and Coastal Environment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
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| Abstract: |
| Lead (Pb) tends to precipitate in seawater, which could influence the calculation of effect value in toxicity tests. In this study, the toxicity of Pb in seawater and the impact of precipitation on acute toxicity were investigated through the acute toxicity test of metals to Perinereis aibuhitensis, a widely distributed benthic invertebrate in China, and Artemia salina, which is a commonly used model organism in marine ecotoxicology. The precipitates appeared in all exposure solutions with nominal Pb concentrations ranging from 18.7 to 1 200 mg/L, whether prepared by artificial or natural seawater. According to the elemental compositions of precipitates detected by scanning electron microscopy and energy-dispersive X-ray, the main components of the precipitate were PbCl2and PbCO3. The actual concentrations of Pb detected by inductively coupled plasma mass spectrometry were just 1/15 to 1/2 of the nominal concentrations. The 96 h/48 h LC50 values of Pb to Perinereis aibuhitensis and Artemia salina calculated by actual concentrations were less than 1/10 of that calculated by nominal concentrations. Comparing the 96 h LC50 of Pb, Cd, and Cu to Perinereis aibuhitensis and Artemia salina, Pb showed less toxicity than Cu and Cd. Comparing the acute toxicity data of Pb in previous studies, Pb was relatively more toxic to larval marine organisms but less or not toxic to adult marine organisms at its solubility limit in seawater. Considering the precipitation characteristic of Pb in seawater, a low-dose chronic exposure experiment to the larva of marine species is quite beneficial when evaluating the Pb ecosystem risk. |
| Key words: Pb metals seawater precipitation toxicity effect |
